The present invention relates to a symmetric double phonic-diaphram volume-enhancing device and in particular, to such a device that is provided with two sets of opposite corresponding resonance cavities, one in the upper portion thereof and the other in the lower portion thereof. The upper resonance cavity is formed in such a way that a upper cavity based provided with spiral ribs is joined by a cover body and an arcuate body is joined to the top of the upper resonance cavity. The lower resonance cavity is formed in such a way that a lower cavity base, which is provided with a funnel-type opening, is joined to a cover body, and a base body is also joined to the bottom of the lower resonance cavity. A piezo-electric-type diaphragm which comprises a vibration diaphragm and start-up plate is provided on each of the two resonance cavities respectively. Conductive wires are connected to the vibration diaphragm and the start-up plate respectively. Electrical signals are applied to the conductive wires to cause the piezo-electric type diaphragm to vibrate back and forth due to piezo-electric effects. Sound waves thus generated by the vibrations produce sound waves on the two opposite resonance cavities, so that sound waves released from the sound outlet and out of the spiral channels and opening, therefore, this is a device having two-plate piezo-electric type diaphgrams provided at the same volume to double the sound output thereof.
The present invention relates to a symmetric double phonic diaphragm volume-enhancing device and, in particular, to a piezo-electric-type loud speaker/public address structure which employs the two sets of opposite corresponding resonance cavities, each of the resonance cavities having a piezo-electric-type diaphragm composed of a vibration diaphragm and a start-up plate. The piezo-electric effect makes the electric power diaphragm form back and forth vibrations to reach the doubled volume through opposite vibrations produced by reach the doubled sound through the two plates of piezo-electric-type diagragm to generate sound waves.
Conventional electric power-type electrical sound changing devices are applicable to alarms and loud speakers. Piezo-electric-type loud speakers turn electrical signals into mechanical vibrations and sound vibrations, so the vibration diaphragms extend and retract along their surface. Such extensible and retractible vibrations of the vibration diaphragms form sound waves. The structure of conventional piezo-electric-type loud speakers are mainly single resonance cavity structure with only a single piezo-electric-type diaphragm, so when the piezo-electric-type diaphragm are led out by two conductive wires and also fed with electrical signals, the signal plate piezo-electric-type diaphragm extends and retracts along its extended direction due to the piezo-electric effect to form vibrations in the back and forth direction, thereby transmitting sound waves by vibrations. Conventional piezo-electric-type can generate vibrations to produce unidirectional volume but cannot achieve a more desirable stronger sound output and if and when a higher volume is required, their volume must be increased to achieve the purpose which often causes limits on their efficiency.
The symmetric double phonic diaphragm volume-enhancing device of the present invention seeks to obviate or mitigate the above-mentioned defects.